Fire safety requirements related to ship cabins set certain requirements for the wall structures of the cabins. For example cabin walls compliant with fire proof class B-15 of International Maritime Organization (IMO Resolution A.754(18) regarding Fire Resistance Tests) typically have a thickness of about 30 mm, and a wall structure comprising an inner and an outer metal surface, and a mineral wool insulator layer between the metal surfaces. This structure causes problems especially in the sanitary units of the cabins, where the metal surface toward the humid sanitary unit easily rusts. Thus, the wall structures of sanitary units have to be renewed for visual reasons and because corroded wall surfaces no longer fulfil the fire safety regulations. Similar problems can be faced with other fire proof classes such as C-0 and B-0, commonly used in ship cabins.
The repair of corroded wall structures is traditionally performed by demolishing the old wall structures and building a new wall step by step on location. Additionally, the sanitary fixtures must also be detached and generally renewed in connection with the demolishing.
In connection with a normal visiting of a cruise ship to the harbor, the visiting time is generally short, wherefore performing the multistage and time-consuming repairs according to the traditional way is difficult. When the ship is in use and it has a lot of passengers, rebuilding the wall structures is difficult, since the repairing comprises several work stages, which cause noise and dust problems. In other words repairing the cabins while the ship is in use is practically impossible by using the traditional way. In a large cruise ship, there can be a remarkable number of cabins to be repaired, so a part or even all of the cabins are out of use in connection with the repair. Repairing all of the cabins at one time requires a lot of time, whereby the cruise ship is out of use, and this is not economically profitable.